How it was before the mod? Try to remove blutack and whatever else you put in there. Another thing, make sure that you install earpads right (left, right, top, down orientation) and that all tabs securely clicked in place. Double check that you didn't block bass ports on top.
They have pretty good, balanced, definitely not lacking by *my standards*, bass, but for bassheads V-Moda is probably a better option.
Edited by Andrew_WOT - 10/6/13 at 11:16am